Cutting implements for cables



Dec. 26, 1967 F. SONNBERGER 3,359,636

CUTTING IMPLEMENTS FOR CABLES Filed Aug. 6, 1965 lI693I 22 I4 19b 7 l3 l2 v F/G.4 16a 2] 22 15 20b 79b ,7 7 i I 7L! I fl A J N J United States Patent 3,359,636 CUTTING IMPLEMENTS FOR CABLES Felix Sonnberger, Kettengasse 22-44, Wurzburg, Germany Filed Aug. 6, 1965, Ser. No. 477,775 Claims priority, application Germany, Aug. 8, 1964,

4 Claims. 61. 30-180 ABSTRACT OF THE DISCLOSURE A handle-actuated hydraulic pump combined with a hydraulic cylinder and piston. A two-part tool holding head is mounted on the cylinder, one part of the head providing a guide for a slidable cutter blade actuated by This invention relates to a novel manually operable cutting implement, in which cutting, pressing or nipping tools must be moved relative to each other with relatively large forces. The invention relates particularly to shears for cables and ropes.

In ordertoenable the action of large forces at the working or clamping faces of a tool, pincers or shears have previously been provided with lever arms of suitable length; In other cases, the relatively movable parts are displaceable with the aid of screw threads. All these implements have the disadvantage that the implement must be operated with both hands virtually in all applications. In many cases, the space which is available is not suflicient for this mode of operation and for accommodating the long lever arms. When cutting electrical power cables, telecommunications cables or ladder ropes on masts, or reinforcing rods on building sites, as well as when cutting barbed wire barriers, the person assigned to such job has often only one hand available for the work because he needs the second hand to hold himself or, e.g., a firearm. For the reasons stated above or because the necessary cutting pressures cannot be achieved with the known, manually operable cutting implements (e.g., when cutting steel wire ropes, large yarn ropes etc.), many of such operations must be carried out with other tools, such as steel-cutting saws, or complicated safety provisions are required for many operations, or scaffolds must be erected, only in order to enable the operator to use both hands in the operation of implements of the kind defined.

It is an object of the invention to provide a cutting implement which enables the generation of large working forces and may be readily designed for operation with one hand, further, which has only a small over-all length and can be used for a wide range of operations.

A cutting implement according to the invention is essentially characterized by a hydraulic displacement pump, which is accommodated in one handle and is operable by means of a second handle and operates a hydraulic jack, which is combined with the pump in a unit, the stationary part of the jack having secured wit a holder for cutting tools, which are adapted to be driven by the adjustable part of the jack. The displacement pump enables .an adjustment of the amount of liquid which is displaced in one stroke or of the capacity of the pump so that different transmission ratios may be selected and sufi'iciently large forces are available for most cutting operations to be performed with a manually operable implement, even if the displacement pump is arranged for being operated with one hand, as is preferred. The basic unit, which comprises the pump and jack, may have secured to it various cutting tools, e.g., for cables, small or large ropes, reinforcing bars, as well as other shears, pincers, gripping jaws or punches.

Further details, advantages and possible developments of the invention will become apparent from the subsequent description of the accompanying drawings.

In these drawings, embodiments of the invention are show by way of example.

FIG. 1 is an elevation showing an implement which carries a tool for cutting multi-conductor cables.

FIG. 2 is an enlarged sectional view of the implement Of FIG. 1.

FIG. 3 is a view similar to FIG. 1 and shows .an implement provided with a tool which is particularly intended for cutting steel wire ropes and large yarn ropes.

FIG. 4 is an enlarged sectional view of the implement of FIG. 3.

With reference to FIG. 1, the basic unit comprises two hand levers 1, 2. The hand lever 1 carries a container 3. A plunger, which is operable by a stem 4, extends laterally into this container 3. A pivotal movement of the hand lever 2, which is pivotally mounted at 5, causes the plunger to pump the liquid contained in the container 3 into the cylinder 6 of a jack or cylinder-piston unit so that a piston 7 of this jack is pushed out. The hand lever 2 is provided with a stop 8 for limiting the pivotal movement of the hand lever and the depression of the stem 4. A spring is provided for returning the stem 4 and the plunger connected to it after each stroke. Alternatively, the stem 4 might-be pivoted to the lever 2 and an expanding spring might be provided between the hand levers 1, 2. The piston 7 can be extended by the pump when the latter is being operated by the stem 4 and a check valve is provided to hold the piston in any extended position. The piston 7 is returned by a return spring, which is arranged outside or inside the cylinder-piston unit and which cannot become effective until the return flow of liquid from the cylinder 6 into the oil container 3 has been enabled by the operation of a handwheel 9 to open the check valve.

The hand levers 1, 2 and the hand wheel 9 can be operated with one hand. The cylinder 6 is provided at its end with screw threads 10, a bayonet joint element or the like, in order to facilitate the mounting of a tool holder. According to FIGS. 1 and 3 the tool holder comprises an annular nut 11, which has extension lugs 12, to which the tools can be secured with the aid of bolts 13 or pivot pins.

The tool for cutting multi-conductor cables, such as telephone cables, which is shown in FIGS. 1 and 2 comprises a gripping or holding head, which comprises two members 16, 17, that are connected to each other by a pivot pin 14 and a locking pin 15, and defines an aperture 18 for a cable to be cut. When the cable has been inserted and the holding head has been closed, longitudinal guides provided on the two members 16, 17 are in alignment so that a cutter blade 19 can be moved with the aid of the piston 7 across the aperture 18 and a cable which has been gripped is neatly severed by this opera tion. As is shown in FIGS. 1 and 2, the cutting edge 20 of the blade 19 may be oblique.

Different cutting tools may be used for cables which differ in diameter, or one and the same holding head may be used for replaceably mounting different cutter blades that are selected in view of the diameter of the different cables.

One and the same tool may be provided with two jointly operable cutter blades arranged one beside the other and having their cutting edges preferably spaced in the longitudinal direction of the knife. Such a tool may be used for cutting short pieces out of a cable. The spacing of the cutting edges ensures that one cutting edge will not engage the cable until the other has already cut through a large part of the cable.

The tool shown in FIGS. 3 and 4 for cutting wire ropes is similar to the implement shown in FIGS. 1 and 2 so that like reference characters are used for like parts. The cutter blade 19b is movable by the piston 7 across the opening 18 and cooperates with a stationary cutter blade 21, which has a cutting edge 22 and is removably positioned in .a grooved seat 23 formed in the member 16a. The cutting edges 20b, 22 of the blades 1%, 21 are aligned and these cutting edges are defined by opposite, bevelled surfaces of each blade which have an included angle of less than 30, and preferably less than 15 at the cutting edge. As a result, the blades consisting of a material which is harder than the ropes to be cut will indent the individual wires of the ropes and will then break ofr these wires by the wedge .action so that even thick steel wire ropes can be cut with the aid of relatively small displacing forces. In practice, steel wire ropes 34 mm. in diameter have been satisfactorily severed with the aid of cutting forces of 2000 kg. applied to the blades.

What is claimed is:

1. In a cable cutting implement, the combination of a hydraulic displacement pump, a pair of coacting handles provided on said pump for actuating the same, a hydraulic cylinder combined as a unit with said pump and including a slidable piston which is projectable outwardly from said cylinder when the pump is actuated by said handles, a tool holding head comprising a first holder member mounted on said hydraulic cylinder and extending axially outwardly therefrom beyond said piston, a second holder member connected to the outer end of the first holder member .and ooacting therewith to provide a normally closed aperture for receiving a cable to be cut, a movable cutter blade slidably guided in said first holder member and operatively connected to said piston, and a stationary cutter blade mounted in a seat (formed in said second holder member for coaction with said movable blade, said movable and stationary blades having opposing aligned cutting edges adapted to come together in a plane intersecting said cable receiving aperture when the movable blade is slid toward the stationary blade by said piston.

2. The device as defined in claim 1 together with a pivot connecting the second holder member to the first holder member at one side of said tool holding head whereby said aperture may be opened for placement of a cable therein, and a fastener provided at the other side of the tool holding head for releasably locking the holder members together in the closed position of said aperture.

3. The device as defined in claim 1 wherein said cutting edges are defined by opposite bevelled surfaces of each blade having an included angle of less than 30 at the cutting edge.

4. The device as defined in claim 1 wherein said cutting edges are defined by opposite bevelled surfaces of each blade having an included angle of less than 15 at the cutting edge.

References Cited UNITED STATES PATENTS 260,395 7/1882 Hotchkiss 30-349 2,096,574 10/1937 Denny 81-301 2,236,833 4/1941 Pell et al 30-182 X 2,248,642 7/1941 Phillips 30180 2,688,231 9/1954 Northcutt 81-301 X 2,696,850 12/1954 Peterson 81-301 X 3,008,234 11/1961 Mattera 30-228 3,152,397 10/1964 Adam 30-180 X WILLIAM FELDMAN, Primary Examiner. J. C. PETERS, Assistant Examiner. 

1. IN A CABLE CUTTING IMPLEMENT, THE COMBINATION OF A HYDRAULIC DISPLACEMENT PUMP, A PAIR OF COACTING HANDLES PROVIDED ON SAID PUMP FOR ACTUATING THE SAME, A HYDRAULIC CYLINDER COMBINED AS A UNIT WITH SAID PUMP AND INCLUDING A SLIDABLE PISTON WHICH IS PROJECTABLE OUTWARDLY FROM SAID CYLINDER WHEN THE PUMP IS ACTUATED BY SAID HANDLES, A TOOL HOLDING HEAD COMPRISING A FIRST HOLDER MEMBER MOUNTED ON SAID HYDRAULIC CYLINDER AND EXTENDING AXIALLY OUTWARDLY THEREFROM BEYOND SAID PISTON, A SECOND HOLDER MEMBER CONNECTED TO THE OUTER END OF THE FIRST HOLDER MEMBER AND COACTING THEREWITH TO PROVIDE A NORMALLY CLOSED APERTURE FOR RECEIVING A CABLE TO BE CUT, A MOVABLE CUTTER BLADE SLIDABLY GUIDED IN SAID FIRST HOLDER MEMBER AND OPERATIVELY CONNECTED TO SAID PISTON, AND A STATIONARY CUTTER BLADE MOUNTED IN A SEAT FORMED IN SAID SECOND HOLDER MEMBER FOR COACTION WITH SAID MOVABLE BLADE, SAID MOVABLE AND STATIONARY BLADES HAVING OPPOSING ALIGNED CUTTING EDGES ADAPTED TO COME TOGETHER IN A PLANE INTERSECTING SAID CABLE RECEIVING APERTURE WHEN THE MOVABLE BLADE IS SLIDE TOWARD THE STATIONARY BLADE BY SAID PISTON. 